Core C: Peptides - The overall mission of the Peptide Core is to provide the resources and services needed to select, screen, sequence, synthesize, label, and analyze the peptides to be used in the Primary and Task Specific Projects for preferential binding and detection of dysplasia in the gastrointestinal tract. Chung Owyang, MD is the Director of Core C: Peptides for this proposed NTR Research Center. Dr. Owyang is also the P.I. of the Gastroenterology Peptide Research Core Center at the University of Michigan, an NIH/NIDDK funded Digestive Disease Center whose mission is to investigate the functional properties and signaling mechanisms of gut peptides. He provides a wealth of experience for guiding research in the peptide binding interactions and target identification of cell surface receptors associated with neoplastic transformation in the digestive tract. Henriette Remmer, PhD, is the Co-Director of this Core. She is also the Director of the Protein Structure Core Facility at the University of Michigan, and has significant experience in techniques of peptide synthesis and protein structure analysis. Dr. Remmer will be available to the network investigators as a resource for consultation regarding all steps of development, synthesis, and analysis of peptides as probes for the detection of pre-malignant mucosa in the digestive tract. Henriette Remmer, PhD, is the Co-Director of this Core. She is also the Director of the Protein Structure Core Facility at the University of Michigan, and has significant experience in techniques of peptide synthesis and protein structure analysis. Dr. Remmer will be available to the network investigators as a resource for consultation regarding all steps of development, synthesis, and analysis of peptides as probes for the detection of pre-malignant mucosa in the digestive tract. Xiaoju (George) Wang, Ph.D is also a Co-Director for Core C: Peptides for this NTR Research Center. Dr. G Wang has significant experience in techniques of phage display, in particular with employing high-throughput phage epitope microarrays and multiplexed protein/epitope microarrays. These resources will be valuable for performing peptide screening to identify optimal candidates for subsequent clinical use, and will be available to all of the investigators in the network.